release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/staging/iio/iio.h

   1 /* The industrial I/O core
   2  *
   3  * Copyright (c) 2008 Jonathan Cameron
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  */
   9
  10 #ifndef _INDUSTRIAL_IO_H_
  11 #define _INDUSTRIAL_IO_H_
  12
  13 #include <linux/device.h>
  14 #include <linux/cdev.h>
  15 #include "sysfs.h"
  16 #include "chrdev.h"
  17
  18 /* IIO TODO LIST */
  19 /*
  20  * Provide means of adjusting timer accuracy.
  21  * Currently assumes nano seconds.
  22  */
  23
  24 /* Event interface flags */
  25 #define IIO_BUSY_BIT_POS 1
  26
  27 struct iio_dev;
  28
  29 /**
  30  * iio_get_time_ns() - utility function to get a time stamp for events etc
  31  **/
  32 static inline s64 iio_get_time_ns(void)
  33 {
  34         struct timespec ts;
  35         /*
  36          * calls getnstimeofday.
  37          * If hrtimers then up to ns accurate, if not microsecond.
  38          */
  39         ktime_get_real_ts(&ts);
  40
  41         return timespec_to_ns(&ts);
  42 }
  43
  44 /**
  45  * iio_add_event_to_list() - Wraps adding to event lists
  46  * @el:         the list element of the event to be handled.
  47  * @head:       the list associated with the event handler being used.
  48  *
  49  * Does reference counting to allow shared handlers.
  50  **/
  51 void iio_add_event_to_list(struct iio_event_handler_list *el,
  52                            struct list_head *head);
  53
  54 /**
  55  * iio_remove_event_from_list() - Wraps removing from event list
  56  * @el:         element to be removed
  57  * @head:       associate list head for the interrupt handler.
  58  *
  59  * Does reference counting to allow shared handlers.
  60  **/
  61 void iio_remove_event_from_list(struct iio_event_handler_list *el,
  62                                 struct list_head *head);
  63
  64 /* Device operating modes */
  65 #define INDIO_DIRECT_MODE               0x01
  66 #define INDIO_RING_TRIGGERED            0x02
  67 #define INDIO_RING_HARDWARE_BUFFER      0x08
  68
  69 #define INDIO_ALL_RING_MODES (INDIO_RING_TRIGGERED | INDIO_RING_HARDWARE_BUFFER)
  70
  71 /* Vast majority of this is set by the industrialio subsystem on a
  72  * call to iio_device_register. */
  73
  74 /**
  75  * struct iio_dev - industrial I/O device
  76  * @id:                 [INTERN] used to identify device internally
  77  * @dev_data:           [DRIVER] device specific data
  78  * @modes:              [DRIVER] operating modes supported by device
  79  * @currentmode:        [DRIVER] current operating mode
  80  * @dev:                [DRIVER] device structure, should be assigned a parent
  81  *                      and owner
  82  * @attrs:              [DRIVER] general purpose device attributes
  83  * @driver_module:      [DRIVER] module structure used to ensure correct
  84  *                      ownership of chrdevs etc
  85  * @num_interrupt_lines:[DRIVER] number of physical interrupt lines from device
  86  * @interrupts:         [INTERN] interrupt line specific event lists etc
  87  * @event_attrs:        [DRIVER] event control attributes
  88  * @event_conf_attrs:   [DRIVER] event configuration attributes
  89  * @event_interfaces:   [INTERN] event chrdevs associated with interrupt lines
  90  * @ring:               [DRIVER] any ring buffer present
  91  * @mlock:              [INTERN] lock used to prevent simultaneous device state
  92  *                      changes
  93  * @scan_el_attrs:      [DRIVER] control of scan elements if that scan mode
  94  *                      control method is used
  95  * @scan_count: [INTERN] the number of elements in the current scan mode
  96  * @scan_mask:          [INTERN] bitmask used in masking scan mode elements
  97  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
  98  * @scan_timestamp:     [INTERN] does the scan mode include a timestamp
  99  * @trig:               [INTERN] current device trigger (ring buffer modes)
 100  * @pollfunc:           [DRIVER] function run on trigger being recieved
 101  **/
 102 struct iio_dev {
 103         int                             id;
 104         void                            *dev_data;
 105         int                             modes;
 106         int                             currentmode;
 107         struct device                   dev;
 108         const struct attribute_group    *attrs;
 109         struct module                   *driver_module;
 110
 111         int                             num_interrupt_lines;
 112         struct iio_interrupt            **interrupts;
 113         struct attribute_group          *event_attrs;
 114         struct attribute_group          *event_conf_attrs;
 115
 116         struct iio_event_interface      *event_interfaces;
 117
 118         struct iio_ring_buffer          *ring;
 119         struct mutex                    mlock;
 120
 121         struct attribute_group          *scan_el_attrs;
 122         int                             scan_count;
 123
 124         u32                             scan_mask;
 125         u32                             *available_scan_masks;
 126         bool                            scan_timestamp;
 127         struct iio_trigger              *trig;
 128         struct iio_poll_func            *pollfunc;
 129 };
 130
 131 /*
 132  * These are mainly provided to allow for a change of implementation if a device
 133  * has a large number of scan elements
 134  */
 135 #define IIO_MAX_SCAN_LENGTH 31
 136
 137 /* note 0 used as error indicator as it doesn't make sense. */
 138 static inline u32 iio_scan_mask_match(u32 *av_masks, u32 mask)
 139 {
 140         while (*av_masks) {
 141                 if (!(~*av_masks & mask))
 142                         return *av_masks;
 143                 av_masks++;
 144         }
 145         return 0;
 146 }
 147
 148 static inline int iio_scan_mask_query(struct iio_dev *dev_info, int bit)
 149 {
 150         u32 mask;
 151
 152         if (bit > IIO_MAX_SCAN_LENGTH)
 153                 return -EINVAL;
 154
 155         if (!dev_info->scan_mask)
 156                 return 0;
 157
 158         if (dev_info->available_scan_masks)
 159                 mask = iio_scan_mask_match(dev_info->available_scan_masks,
 160                                         dev_info->scan_mask);
 161         else
 162                 mask = dev_info->scan_mask;
 163
 164         if (!mask)
 165                 return -EINVAL;
 166
 167         return !!(mask & (1 << bit));
 168 };
 169
 170 static inline int iio_scan_mask_set(struct iio_dev *dev_info, int bit)
 171 {
 172         u32 mask;
 173         u32 trialmask = dev_info->scan_mask | (1 << bit);
 174
 175         if (bit > IIO_MAX_SCAN_LENGTH)
 176                 return -EINVAL;
 177         if (dev_info->available_scan_masks) {
 178                 mask = iio_scan_mask_match(dev_info->available_scan_masks,
 179                                         trialmask);
 180                 if (!mask)
 181                         return -EINVAL;
 182         }
 183         dev_info->scan_mask = trialmask;
 184         dev_info->scan_count++;
 185
 186         return 0;
 187 };
 188
 189 static inline int iio_scan_mask_clear(struct iio_dev *dev_info, int bit)
 190 {
 191         if (bit > IIO_MAX_SCAN_LENGTH)
 192                 return -EINVAL;
 193         dev_info->scan_mask &= ~(1 << bit);
 194         dev_info->scan_count--;
 195         return 0;
 196 };
 197
 198 /**
 199  * iio_scan_mask_count_to_right() - how many scan elements occur before here
 200  * @dev_info: the iio_device whose scan mode we are querying
 201  * @bit: which number scan element is this
 202  **/
 203 static inline int iio_scan_mask_count_to_right(struct iio_dev *dev_info,
 204                                                 int bit)
 205 {
 206         int count = 0;
 207         int mask = (1 << bit);
 208         if (bit > IIO_MAX_SCAN_LENGTH)
 209                 return -EINVAL;
 210         while (mask) {
 211                 mask >>= 1;
 212                 if (mask & dev_info->scan_mask)
 213                         count++;
 214         }
 215
 216         return count;
 217 }
 218
 219 /**
 220  * iio_device_register() - register a device with the IIO subsystem
 221  * @dev_info:           Device structure filled by the device driver
 222  **/
 223 int iio_device_register(struct iio_dev *dev_info);
 224
 225 /**
 226  * iio_device_unregister() - unregister a device from the IIO subsystem
 227  * @dev_info:           Device structure representing the device.
 228  **/
 229 void iio_device_unregister(struct iio_dev *dev_info);
 230
 231 /**
 232  * struct iio_interrupt - wrapper used to allow easy handling of multiple
 233  *                      physical interrupt lines
 234  * @dev_info:           the iio device for which the is an interrupt line
 235  * @line_number:        associated line number
 236  * @id:                 idr allocated unique id number
 237  * @irq:                associate interrupt number
 238  * @ev_list:            event handler list for associated events
 239  * @ev_list_lock:       ensure only one access to list at a time
 240  **/
 241 struct iio_interrupt {
 242         struct iio_dev                  *dev_info;
 243         int                             line_number;
 244         int                             id;
 245         int                             irq;
 246         struct list_head                ev_list;
 247         spinlock_t                      ev_list_lock;
 248 };
 249
 250 #define to_iio_interrupt(i) container_of(i, struct iio_interrupt, ev_list)
 251
 252 /**
 253  * iio_register_interrupt_line() - Tell IIO about interrupt lines
 254  *
 255  * @irq:                Typically provided via platform data
 256  * @dev_info:           IIO device info structure for device
 257  * @line_number:        Which interrupt line of the device is this?
 258  * @type:               Interrupt type (e.g. edge triggered etc)
 259  * @name:               Identifying name.
 260  **/
 261 int iio_register_interrupt_line(unsigned int                    irq,
 262                                 struct iio_dev                  *dev_info,
 263                                 int                             line_number,
 264                                 unsigned long                   type,
 265                                 const char                      *name);
 266
 267 void iio_unregister_interrupt_line(struct iio_dev *dev_info,
 268                                    int line_number);
 269
 270
 271
 272 /**
 273  * iio_push_event() - try to add event to the list for userspace reading
 274  * @dev_info:           IIO device structure
 275  * @ev_line:            Which event line (hardware interrupt)
 276  * @ev_code:            What event
 277  * @timestamp:          When the event occurred
 278  **/
 279 int iio_push_event(struct iio_dev *dev_info,
 280                   int ev_line,
 281                   int ev_code,
 282                   s64 timestamp);
 283
 284 /**
 285  * __iio_push_event() - tries to add an event to the list associated with a chrdev
 286  * @ev_int:             the event interface to which we are pushing the event
 287  * @ev_code:            the outgoing event code
 288  * @timestamp:          timestamp of the event
 289  * @shared_pointer_p:   the shared event pointer
 290  **/
 291 int __iio_push_event(struct iio_event_interface *ev_int,
 292                     int ev_code,
 293                     s64 timestamp,
 294                     struct iio_shared_ev_pointer*
 295                     shared_pointer_p);
 296 /**
 297  * __iio_change_event() - change an event code in case of event escalation
 298  * @ev:                 the event to be changed
 299  * @ev_code:            new event code
 300  * @timestamp:          new timestamp
 301  **/
 302 void __iio_change_event(struct iio_detected_event_list *ev,
 303                         int ev_code,
 304                         s64 timestamp);
 305
 306 /**
 307  * iio_setup_ev_int() - configure an event interface (chrdev)
 308  * @name:               name used for resulting sysfs directory etc.
 309  * @ev_int:             interface we are configuring
 310  * @owner:              module that is responsible for registering this ev_int
 311  * @dev:                device whose ev_int this is
 312  **/
 313 int iio_setup_ev_int(struct iio_event_interface *ev_int,
 314                      const char *name,
 315                      struct module *owner,
 316                      struct device *dev);
 317
 318 void iio_free_ev_int(struct iio_event_interface *ev_int);
 319
 320 /**
 321  * iio_allocate_chrdev() - Allocate a chrdev
 322  * @handler:    struct that contains relevant file handling for chrdev
 323  * @dev_info:   iio_dev for which chrdev is being created
 324  **/
 325 int iio_allocate_chrdev(struct iio_handler *handler, struct iio_dev *dev_info);
 326 void iio_deallocate_chrdev(struct iio_handler *handler);
 327
 328 /* Used to distinguish between bipolar and unipolar scan elemenents.
 329  * Whilst this may seem obvious, we may well want to change the representation
 330  * in the future!*/
 331 #define IIO_SIGNED(a) -(a)
 332 #define IIO_UNSIGNED(a) (a)
 333
 334 extern dev_t iio_devt;
 335 extern struct bus_type iio_bus_type;
 336
 337 /**
 338  * iio_put_device() - reference counted deallocation of struct device
 339  * @dev: the iio_device containing the device
 340  **/
 341 static inline void iio_put_device(struct iio_dev *dev)
 342 {
 343         if (dev)
 344                 put_device(&dev->dev);
 345 };
 346
 347 /**
 348  * to_iio_dev() - get iio_dev for which we have the struct device
 349  * @d: the struct device
 350  **/
 351 static inline struct iio_dev *to_iio_dev(struct device *d)
 352 {
 353         return container_of(d, struct iio_dev, dev);
 354 };
 355
 356 /**
 357  * iio_dev_get_devdata() - helper function gets device specific data
 358  * @d: the iio_dev associated with the device
 359  **/
 360 static inline void *iio_dev_get_devdata(struct iio_dev *d)
 361 {
 362         return d->dev_data;
 363 }
 364
 365 /**
 366  * iio_allocate_device() - allocate an iio_dev from a driver
 367  **/
 368 struct iio_dev *iio_allocate_device(void);
 369
 370 /**
 371  * iio_free_device() - free an iio_dev from a driver
 372  * @dev: the iio_dev associated with the device
 373  **/
 374 void iio_free_device(struct iio_dev *dev);
 375
 376 /**
 377  * iio_put() - internal module reference count reduce
 378  **/
 379 void iio_put(void);
 380
 381 /**
 382  * iio_get() - internal module reference count increase
 383  **/
 384 void iio_get(void);
 385
 386 /**
 387  * iio_device_get_chrdev_minor() - get an unused minor number
 388  **/
 389 int iio_device_get_chrdev_minor(void);
 390 void iio_device_free_chrdev_minor(int val);
 391
 392 /**
 393  * iio_ring_enabled() - helper function to test if any form of ring is enabled
 394  * @dev_info:           IIO device info structure for device
 395  **/
 396 static inline bool iio_ring_enabled(struct iio_dev *dev_info)
 397 {
 398         return dev_info->currentmode
 399                 & (INDIO_RING_TRIGGERED
 400                    | INDIO_RING_HARDWARE_BUFFER);
 401 };
 402
 403 struct idr;
 404
 405 int iio_get_new_idr_val(struct idr *this_idr);
 406 void iio_free_idr_val(struct idr *this_idr, int id);
 407 #endif /* _INDUSTRIAL_IO_H_ */